The detection and removal of contaminants in a fluid finds application across many fields, including the field of water consumption and recycling. In many parts of the world, clean water is becoming a scarce commodity. Water treatment to remove contaminants can be effective, but is often costly, or uses technology that is not readily available. One area of high water consumption is the household shower, in which water is continuously distributed from a showerhead and collected by a drain below. The water in the drain is discarded with other forms of wastewater, but is often less contaminated than wastewater from other sources, especially during times when no soap is being used. Moreover, the types of contaminants that enter the water in the shower are typically limited, and enter sporadically. As such, a large amount of the water entering a drain in a household shower is relatively clean.
Previous attempts at recycling showers involve manual user control to change the outflow direction of the used water to reuse the water when it is clean (WO 2004/101902), or have filtration means to filter and pump to recirculate all of the wastewater from the shower (WO 2005/083188). While effective to a certain extent, these methods are inherently limited in their ability to control the recycling of shower water with a high degree of efficiency or with a high degree of confidence regarding a true level of contamination of the used water.
In recycling shower systems of the prior art, removing certain particulate contaminants from recycled water was found to be an important issue. It would therefore be possible to design a shower that removes all particulate contaminants with a filter pore size smaller than the smallest contaminant. This system would, however, require a pump of significant power/energy input in order to force water through a filtering device of such small porosity and would not permit the removal of soluble contaminants.